<!DOCTYPE html>
<html lang="en-gb">
<body>
<h1>run JavaScript Ext demo</h1>
</body>
<script type="text/javascript">
function testString() {
  return "hello, world";
}
function testNumber() {
  return 01234567;
}
function testBoolean() {
  return true;
}
function testArrayBuffer() {
  let buffer = new ArrayBuffer(12);
  buffer[0] = 'a';
  return buffer
}
function testArray() {
  let a = Array("apple", "banana", "cherry");
  return a
}
</script>
</html>